Batts bureaucrat says he was powerless

A senior bureaucrat behind the home insulation scheme was aware of safety risks but felt he couldn't challenge more powerful public servants.

Kevin Keeffe, a former assistant secretary in the environment department, has told a royal commission he didn't question plans to allow foil in Labor's $2.8 billion program despite knowing about foil-related deaths in New Zealand during 2007.

"Can I remind you of my position?" he said under questioning from counsel assisting Keith Wilson, QC, on Tuesday.

"I'm assistant secretary. I have above me in the chair the first assistant secretary, a deputy secretary, a secretary and a minister.